#define ECHO_PIN 2
#define TRIG_PIN 15
#define lampu1 21
#define lampu2 19
#define lampu3 18
#define lampu4 5

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(ECHO_PIN, INPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(lampu1, OUTPUT);
  pinMode(lampu2, OUTPUT);
  pinMode(lampu3, OUTPUT);
  pinMode(lampu4, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  int waktu = pulseIn(ECHO_PIN, HIGH);
  int jarak = waktu * 0.034 /2;
  Serial.print("Jarak : ");
  Serial.println(jarak);

  if(jarak > 50){
    digitalWrite(lampu1, HIGH);
    digitalWrite(lampu2, LOW);
    digitalWrite(lampu3, LOW);
    digitalWrite(lampu4, LOW);
  } 
   if (jarak > 100){
    digitalWrite(lampu1, HIGH);
    digitalWrite(lampu2, HIGH);
    digitalWrite(lampu3, LOW);
    digitalWrite(lampu4, LOW);
  } 
   if (jarak > 200) {
    digitalWrite(lampu1, HIGH);
    digitalWrite(lampu2, HIGH);
    digitalWrite(lampu3, HIGH);
    digitalWrite(lampu4, LOW);
  } 
   if (jarak > 300) {
    digitalWrite(lampu1, HIGH);
    digitalWrite(lampu2, HIGH);
    digitalWrite(lampu3, HIGH);
    digitalWrite(lampu4, HIGH);
  } else {
    digitalWrite(lampu1, LOW);
    digitalWrite(lampu2, LOW);
    digitalWrite(lampu3, LOW);
    digitalWrite(lampu4, LOW);
  }


}